System of communication with moving vehicles



H. A. AFFEL SYSTEM OF COMMUNICATION WITH MOVING VEHCLES Filed June 18, 1921 ATTORNEY 'Tb all 'inherit may concern;

Be it 'known that LaHERMAN A. Arran, re#

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Hman n.4 arranger nnooknrn, new YORK, assrenon 'ro mannrcanjrntnrnoaan *ann 4'rnniermann COMPANY, A ccnrona'rronorjnnw Yoan.

srsrnin er corrfnunrcarron WITH-Movin@ nnnrcnns.

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siding at Brooklyn, in the county of Kings and State of New York,-have invented cercation with-MovingVehicles, of which the following is a specification.

This invention relates to systems of communication and more particularly to iml()A proved arrangements for communicating with moving vehicles, such as railway trains. lin the arrangements of the invention the same medium is utilized for conveying the telephone or signalV currents to themovin'g vehicle as thatused for supplying the motive power thereto, @such for example as a third rail or an overheadhigh tension power wire. Furthermore in order 'to prevent the power current from causing disturbance in the message and so that a plurality of messages may be transmitted simultaneously, the message or telephone current is superimposed on a high frequency carrier current. In the invention arrangements are also provided Afor improving the transmission by transmitting'the-message currents' primarily over the high tension power wire'and applying them at frequent intervals through interthe route by auxiliary circuits-and powermediate circuits tothe third rail and vehicle, thereby avoiding large attenuation which would result if the message currents were applied directly to the third rail. Other features of the invention will appear more fully from the detailed description hereinafter given.

rlhe invention lmay be more fully understood from the following description -to gether with the accompanying drawing in which is illustrated a circuit diagram of a preferred embodiment thereof.

rlllhe drawing shows an electric railway system comprising the track T having the rails 2 and 3 and the third rail 4. Running in the vicinity of the track is the high tension power line L which is connected to a power supply 1 at a terminal station. Current is supplied to the third rail 'from thehigh tension power line at intervals along sub-stations,such as the circnit 13 and the power sub-station 15. lt is advantageous to have a primary distribution system, such as the high tension power lineL, and frequent cross connections to the third rail, such as circuit 13, vas considerable saving of energy be impossible dueto the higher resistance 'I of the thirdrail. The power sub=stations, A such as A15,' 1n these "auxiliary circuits serve tain Improvements in Systems of 'Comniu-ni p 'and the other filters hereinafter referred to are of the band filter type, disclosed inthe U S. Patent No. 1,227,113 to G. A. Campbell,"and-will readily transmit frequencies within a certain range but will attenuate and extinguish frequencies outside of said range. The band lter .LPF1 will pass the power currents but will prevent the other currents, such as signaling currents, from being transmitted therethrough. In the circuit 13 is thelter LPF5 which will allow the transmission of the high tension power currents but will attenuate and extinguish the signaling currents of carrier frequency utilized. 'i

The telephone transmitting and receiving arrangements 6 are provided in the car. These arrangements are associated with the brush 10 and include thehigh pass filters HPF2 and HPF3 which will prevent the power currents-from interfering with the telephone apparatus but which will readily allow the transmissionzof the telephone currents. There is provided in the receiving branch a detector and amplifier arrangement, shown schematically as 20 as any suitable detecting and amplifying arrangement may be used. In the transmitting branch is provided a modulating arrangement, such as 21, whereby the low frequency telephone currents may be superimposed upon a carrier channel of higher frequency. This modulating device may be fof the .duplexvacuum bulb type illustrated in the U. S. patent to John R. Carson, No.,1,343,307, although other well known types might be utilized. The transmitting and receiving branches are associated with a hybrid coil 22 with' which is'associated the usual'l type of balancing network N2 and the telephone transmitter 23 and the receiver 24.

At some desirable point would be located the stationary telephone station 5. This station wouldibeyinductively related to the high tension line Ifby means of circuit 16. Station 5 would include the high pass filters HPFe and HPF7 similar to l-IPF2 and HPFs, a modulating device 17 similar., to 21 and ampliying and detecting arrangements 18 similar to 20. There would also be provided the hybrid coil 19, a balancing network N, and a jack J to which might be connected telephone apparatus. The high frequency carrier currents which would be transmitted from station 5 would be transmitted inductively through circuit 16 to the v line L. As is well known, whenever a coil or a length of wire through which a current is flowing is placed in the vicinity of a pair conditions of vao Abe se of conductors in a circuit, electromotive forces will be induced in said conductors. If

refect balance existed between the con uctors in the circuit, these electromotive forces might neutralize each other. However, this would be the exception, and, in general, a series component would result which wo-uld give a current iiow in the circuit in series over said pair of conductors. The high fre uency carrier currents accordin ly would ow over .the wires L in series. T ese currents would be transmitted from line L to the third rail over a number of auxiliary circuits, such as 12 and 14. Circuit 12 is inductivelyrelated to line L while circuit 14 is bridged across said line. While alternative arrangements have thus been shown either or both types may be employed. In each of these circuits would ective arrangements which would readily allow transmission of the telephone currents but which would attenuate and extinguish the power currents. These selective arrangementsv are shown in circuit 14 as the high pass filter HPF4 and in circuit 12 as the condenser 11 and an inductance. It is pointed out that auxiliary circuits of the type of 12 or 14 would be` provided at frequent intervals along the route of the car so that there would be frequent cross connections between the rimary distribution system L and the third) rail. As the line L is of copper and is relatively large it furnishes an excellent transmission path for the telephone currents and produces relatively small attenuation. If the telephone system was connected directly to the third .rail the steel rail on the other hand would cause considerable attenuation in the telephone currents. Accordingly with the arrangements of this invention by providing a primary distribution line of low attenuation with frequent cross connection to the third rail, it is possible to save considerable energy and to give greatly improved transmission in a system of this character.

The power circuit or the arrangements disclosed may be traced as follows: from the power source 1, over the high tension primary distribution line L, and thence over one of the circuits, such as 13, and through the sub-power station 15 where the high tension power currents will be translated into low tension currents suitable for operating the car motor. These currents will be transmitted from circuit 13 to the third rail and the grounded car tracks. From the third rail these currents will be transmitted throu h the brush 10, through the low pass lter PF and over circuit 25 to the motor 9, thereby operating the motor and drivin the car. The telephone currents transmitte from station 5 to station 6 on the moving car will be transmitted over the followin path: from telephone a paratus (not shown associated with jack d), to the modulating apparatus 17, where the telephone currents will be superimposed upon a high frequenc carrier current and thence through the hi pass filter HPF e to the circuit 16. From t e circuit 16 these currents will be transmitted by induction to the line L and thence over one of the auxiliary circuits, such as 14, to the third rail and one of the ounded rails. From the third rail these te ephone currents will be transmitted to the shoe 10, through the high pass filter HPF2 to the detecting and amplifying apparatus 20 and thence through the hybrid coil 22 to the telephone receiver 24. Currents transmitted from the moving telephone station 6 would be transmitted over the followin ath: from the transmitter 23 to the moV ating apparatus 21 where these currents would be superimposed upon a high fre uency carrier current and thence throng the high pass filter HPFa, through the shoe 10, to the third rail; from the third rail over one of the circuits, such as 14 or 12, to the high tension line L; from the high tension line L these currents would be transmitted by induction to the circuit 16 and thence through the high pass lter HPF, to the detecting and amplifying apparatus 18, and through the hybrid coll 19 to the telephone receiving apparatus which might be connected to the jack J.

While the invention has been disclosed in certain specific arrangements which are deemed desirable, it is understood that it is capable of embodiment in many and other widely varied forms without departing from the spirit of the invention as defined in the ap ended claims.

at is claimed is:

1. In a system for communicating with movin vehicles, a high tension electric power ine, a secondary distribution line associated with said hig tension line, a moving vehicle having a connection from said secondary line to telephone apparatus in said vehicle, a plurality of auxiliary circuits suitable for the transmission of telephone currents interconnecting said high tension line los d iol seconder-y line nt mn intorrnle nlo the route ot irl lines, d menus for npplymg telephone current to snidl high tension line.

2. lin n' system for oounicnting with moving vehicles, o high tension electric power line, o telephone tion inted with id line whereby high fr uency cnrrier current molnlntod h currents mo be impressed on snig power line, n seconvnry distribution line, o pluity ol 'nunilinry circuito suitnlole for the exclusive trnnsmission of snil telephone currents interconnecting id high tension line ond id secondary line nt frequent intervals nlong the route of said lines, a plurality of auxilnry circuits suitable for the exclusive transmission of power currents interconnecting said high tension line and smid secondary line at frequent intervals clon the route of' scid lines, a moving vehicle avng connecting means with said secondary line, and carrier current telephone apparatus in scid vehicle connected to said connecting means.

lln testimony whereof, l have si ed my nometo this specification this 16th day ol J une, 11921.

HERN A. AFFEL.

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